You may clear CMOS to revoke previous BIOS password. Please turn off power and remove power cord from motherboard before clear CMOS. To clear CMOS, you may follow the instruction below:

If there is a [CMOS_SW] button on motherboard, just press this button to clear CMOS.

If there is a CLR_CMOS (Clearing CMOS Jumper) jumper on the motherboard, you may place a jumper cap to temporarily short the two pins or use a metal object like a screwdriver to touch the two pins for a few seconds. (You may refer to the manual about where CLR_CMOS located.)

If there is no CLR_CMOS jumpers or [CMOS_SW] button on the motherboard, please follow the steps to clear CMOS:

Take out the battery gently and put it aside for about 10 minutes or longer. (Or you can use a metal object to connect the two pins in the battery holder to make them short-circuited.)